N-acyl-2-amino acid amides containing phosphinic esters, process for their preparation, and N-acyl-2-amino acids nitriles as precursors

Abstract

N-acyl-2-amino acid amides containing phosphinic esters, process for their preparation, and N-acyl-2-amino acid nitriles as precursors Phosphorus-containing N-acyl-2-amino acid amides of the general formula (I) ##STR1## where R 1 is alkyl, optionally substituted by halogen or alkoxy, or is benzyl or phenyl, each of which is optionally substituted by alkyl, alkoxy, halogen, nitro or CF 3 , or is cycloalkyl, and R 2 is H, or alkyl, optionally substituted by halogen or alkoxy, or is (CH 2 ) n -phenyl, optionally substituted in the phenyl ring by alkyl, alkoxy, halogen, nitro or CF 3 , where n=0, 1, 2 or 3, are valuable intermediates for the preparation of L-phosphinothricin by enzymatic cleavage, and can be obtained from the corresponding N-acyl-2-amino acid nitrile by selective acid hydrolysis.

I claim: 
     
       1. An N-acyl- 2-amino acid amide of the formula (I) ##STR7## where R 1  is C 1  -C 14  -alkyl which is branched or unbranched and unsubstituted or monosubstituted or polysubstituted by halogen or C 1  -C 6  -alkoxy, or is benzyl or phenyl, benzyl or phenyl being unsubstituted or monosubstituted or polysubstituted in the phenyl ring by C 1  -C 4  -alkyl, C 1  -C 4  -alkoxy, halogen, nitro or trifluoromethyl, or is C 3  -C 10  -cycloalkyl, and R 2  is hydrogen, C 1  -C 14  -alkyl which is unsubstituted or monosubstituted or polysubstituted by halogen or C 1  -C 4  -alkoxy, or is a radical of the formula --(CH 2 ) n  -phenyl which is unsubstituted or monosubstituted to trisubstituted in the phenyl ring by C 1  -C 4  -alkyl, C 1  -C 4  -alkoxy, halogen, nitro or trifluoromethyl and in which n is 0, 1, 2 or 3, with the proviso that R 1  is not ethyl when R 2  is methyl.     
     
     
       2. A compound of the formula (I) as claimed in claim 1, wherein R 1  is unbranched or branched C 1  -C 10  -alkyl or C 1  -C 10  -alkyl which is monosubstituted to trisubstituted by halogen, or is C 5  -C 6  -cycloalkyl, and   R 2  is hydrogen, unbranched or branched C 1  -C 14  -alkyl which is unsubstituted or substituted by one to three radicals from the group comprising halogen and C 1  -C 4  -alkoxy, or is a radical of the formula --(CH 2 ) n  --phenyl, the phenyl ring being unsubstituted or monosubstituted to trisubstituted by halogen and n being 0, 1 or 2.   
     
     
       3. A compound of the formula (I) as claimed in claim 1, wherein R 1  is unbranched C 1  -C 8  -alkyl or cyclohexyl, and   R 2  is C 1  -C 4  -alkyl or benzyl.   
     
     
       4. A compound of the formula (II) ##STR8## wherein R 1  is C 1  -C 14  -alkyl which is branched or unbranched and unsubstituted or monosubstituted or polysubstituted by halogen or C 1  -C 6  -alkoxy, or is benzyl or phenyl, benzyl or phenyl being unsubstituted or monosubstituted or polysubstituted in the phenyl ring by C 1  -C 4  -alkyl, C 1  -C 4  -alkoxy, halogen, nitro or trifluoromethyl, or is C 3  -C 10  -cycloalkyl, and R 2   is a radical of the formula --(CH 2 ) n  -phenyl which is unsubstituted or monosubstituted to trisubstituted in the phenyl ring by C 1  -C 4  -alkyl, C 1  -C 4  -alkoxy, halogen, nitro or trifluoromethyl and in which n is 0, 1, 2 or 3.   
     
     
       5. A compound of the formula II as claimed in claim 4, where R 1  is unbranched or branched C 1  -C 10  -alkyl or C 1  -C 10  -alkyl which is monosubstituted to trisubstituted by halogen, or is C 5  -C 6  -cycloalkyl, and   R 2  is a radical of the formula --(CH 2 ) n  -phenyl, the phenyl ring being unsubstituted or monosubstituted to trisubstituted by halogen and n being 0, 1 or 2.   
     
     
       6. A compound as claimed in claim 4, wherein R 1  is unbranched C 1  -C 8  -alkyl or cyclohexyl, and   R 2  is benzyl.   
     
     
       7. A process for the preparation of a compound of the formula (I) ##STR9## where R 1  is C 1  -C 14  -alkyl which is branched or unbranched and unsubstituted or monosubstituted or polysubstituted by halogen or C 1  -C 6  -alkoxy, or is benzyl or phenyl, benzyl or phenyl being unsubstituted or monosubstituted or polysubstituted in the phenyl ring by C 1  -C 4  -alkyl, C 1  -C 4  -alkoxy, halogen, nitro or trifluoromethyl, or is C 3  -C 10  -cycloalkyl, and R 2  is hydrogen, C 1  -C 14  -alkyl which is unsubstituted or monosubstituted or polysubstituted by halogen or C 1  -C 4  -alkoxy, or is a radical of the formula --(CH 2 ) n  -phenyl which is unsubstituted or monosubstituted to trisubstituted in the phenyl ring by C 1  -C 4  -alkyl, C 1  -C 4  -alkoxy, halogen, nitro or trifluoromethyl and in which n is 0, 1, 2 or 3, which comprises subjecting an N-acyl-2-amiano acid nitrile of the formula (II) ##STR10## where R 1  and R 2  have the meanings indicated in the case of formula (I), to selective acid hydrolysis on the nitrile group, to give the corresponding carboxamide of the formula (I).     
     
     
       8. The process as claimed in claim 7, in which the hydrolysis is carried out in formic acid or aqueous formic acid. 
     
     
       9. The process as claimed in claim 7, in which the hydrolysis is carried out using formic acid in the presence of hydrogen halide. 
     
     
       10. The process as claimed in claim 7, in which a solvent is used which is inert under the reaction conditions. 
     
     
       11. The process as claimed in claim 7, in which the hydrolysis is carried out at 0° to 250° C.